1. Field of the Invention
The invention relates to a hand-held electronic device having a rolled-up screen, and more particularly to the hand-held electronic device having a rolled-up screen that is applicable to a cellular phone or a tablet computer, for which, while a flexible screen thereof is at an initial position by having the flexible screen to be reeled inside a casing via a reeling mechanism, the cellular phone or the tablet computer can perform as a normal cellular phone or tablet computer, and for which, while the flexible screen is at an extended position by having the flexible screen to be pulled out of the casing, the cellular phone or the tablet computer can perform as a device having a broad display screen.
2. Description of the Prior Art
Currently, the hand-held electronic device such as a cellular phone, a personal digital assistant, a GPS guide apparatus, a tablet computer and palm-size electronic play machine is usually equipped with a fixed-size display screen; in particular, a small-size display screen. Such an electronic device having a small-size screen is good in portability, but is ill in the limited display area, by which the image resolution and the applicability of a touch screen are problems. On the other hand, though the display screen can be enlarged so as to enhance the display area, the entertainment quality and the touch-control operability, yet the whole volume occupation is then too large to be in the field of portability or hand-holding. For example, the touch-control display screen for the smart phone has been increased from the 3″ screen. the 4″ screen, and finally to the 5″ screen. In spite that the display screen has been made broader so as to ensure a better screen displaying and the viewing quality, yet such a size for the hand-held electronic device is too much for the female customers. Definitely, for those female customers, the definition of the portable electronic device with an enlarged display screen might not be equal to the hand-held device anymore.
Recently. various flexible screens have been developed, such as Korean Samsung's flexible AMOLED. Japan TDK's flexible OLED, Korean LG Display's plastic electronic paper screen, and Taiwan ITRI's touch AMOLED ultra-thin film screen and so on. Based on the modern technology, the thickness of the flexible touch screen can be down to 0.3 mm, and the flexible touch screen can be rolled into a cylinder with a radius at least less than 2.5 mm. Nevertheless, for the smart phones equipped with the flexible screens, the current development is still stayed in the stage of a prototype model with a flexible screen. Though the flexible screen is introduced to the smart phone, yet the concept of flexibility is at the device body itself, not at the size of the display screen. Namely. though a larger-sized flexible screen can be applied to a smart phone. yet such a bigger size in the screen does only result in a cumbersome machine for the smart phone, which is definitely away from the original design concept in hand-holding and portability.